PP&L is only the second utility in the country to ask for modifications to a boiling-water reactor, although 18 are considering it, said James Raleigh, the Nuclear Regulatory Commission's project manager for Susquehanna.

Detroit Edison Co. has applied to modify its Fermi 2 reactor in Michigan.

The plan, if approved, would allow PP&L to put off construction of any new power plants until at least 2005, and sell excess power to other utilities, said Herbert D. Woodeshick, special assistant to PP&L's president.

Those sales will help the company recover the $40 million project cost in less than five years, he said.

The amount is minor compared to the billions of dollars it would cost to build a nuclear plant today. PP&L spent $4 billion to build Susquehanna 10 years ago.

But the obstacles to building a new plant aren't just financial. Since the Three Mile Island accident in 1978, the nuclear industry has struggled for acceptance in financial, corporate and political circles.

No new nuclear plants have been ordered since 1978.

"This is a minor modification that will not compromise safety in any way, and yet it's very reasonable and economical energy for our customers," Woodeshick said. "We believe it's the prudent thing to do."

But Robert Pollard, a nuclear safety engineer with the Union of Concerned Scientists, said increasing a reactor's power level will put greater pressure on equipment and reduce safety margins.

"They can't build any more plants and they can't sell any more, so they're going to try and boost the power level of the ones they've got," Pollard said of the nation's utilities. "It's not a great idea."

Pollard said he is frustrated in his attempts to obtain all the reports by General Electric on the ability of its reactors to handle power increases. Those he has seen, however, "seem to be more promises than analysis," Pollard said.

"They have to show that more harsh conditions aren't going to increase the probability of having an accident," Pollard said.

Woodeshick and Raleigh said Susquehanna can handle the power increase PP&L is proposing.

Both reactors were licensed to operate at levels below their design strength, Raleigh said. If the modifications are approved, the reactors would operate close to 100 percent of their design strength and generate 100,000 more kilowatts of electricity, he said.

The additional power would increase the pressure inside the reactor vessel by 30 pounds per square inch to a little more than 1,000 pounds per square inch, Woodeshick said.